Shield material

ABSTRACT

Disclosed is a fire-resistant lead-free shield material having high shielding ability against nuclear or electromagnetic radiation, and excellent bending workability and handling performance. The shield material comprises a composite material consisting of an organic material and a metal or metal compound having a nuclear or electromagnetic radiation-shielding ability. The composite material is formed into a given shape, such as a plate shape, and wrapped with a cloth-like sheet formed of glass fibers, metal fibers or carbon fibers. Alternatively, the shield material comprises a shielding element consisting of an elastic polymeric organic compound and a particle having a nuclear or electromagnetic radiation-shielding ability, such a heavy metal or ferrite. The shield material also includes either one of a film made of polyethylene, nylon, polyester or metal, a wire mesh formed of nylon fiber or metal fiber, and a plate- or rod-shaped member having a surface formed with a protrusion, which is compression-bonded onto or in the vicinity of a surface of the shielding element, or inside the shielding element.

TECHNICAL FIELD

The present invention relates to a shield material for use as a shieldagainst nuclear or electromagnetic radiation.

BACKGROUND ART

Heretofore, lead and lead alloys have been used as a material for anuclear radiation shield, in terms of high density and excellentradiation-shielding ability. At the same time, the lead and lead alloysinvolves a problem about poor availability as a shield material for usein an area to be subjected to plasticity working, when the lead or leadalloy-based material has a large thickness, because of its hardlyshaping ability during a deformation process. Recent years, an aggregateof thin fibrous lead strands, so-called lead wools, has beenincreasingly used as a lead-based shield material being capable ofshaping. While the use of lead wools can facilitate deformation andshaping, the material becomes more reduced in density along withincrease in the degree of deformation and causes a problem aboutdeterioration in radiation-shielding performance. Moreover, lead itselfis harmful to humans, and the use of lead has been increasinglyrestricted. Thus, there is the need for developing a lead-free materialusable as a radiation shield.

A heavy-metal plate and a resin-based material prepared by kneading aradiation-shielding powder having a radiation-shielding ability as itsown property, such as iron oxides have been used for shielding againstelectromagnetic radiation. However, these materials have difficulties inbeing shaped through a deformation process, and the resin-based materialcontaining the radiation-shielding powder kneaded thereinto has anotherdisadvantage about fragility and the need for paying particularattention to its handling.

So as to solve disadvantages of a radiation shield material as analternative to the above conventional lead-based material and to meetthe need for environmental public health and flexibility, a radiationshield material comprising a composite material consisting of a metaland an organic material is disclosed in Japanese Patent Laid-OpenPublication No. 08-122492.

However, the fact of the matter is that the composite materialconsisting of the metal and organic material is liable to sufferbreakage or cracks during handling and thereby required to payparticular attention to its handling as heretofore. While the strengthor content of the organic material may be increased as measures againstthis problem, such measures will spoil its original flexibility anddensity, and lead to deterioration in radiation-shielding performance.Moreover, the composite material consisting of the metal and organicmaterial disadvantageously catches fire easily in the event of a fire orabnormal overheating.

DISCLOSURE OF THE INVENTION

It is a general object of the present invention to solve theaforementioned problems of the conventional shield material.

Specifically, it is an object of the present invention to obtain ashield material having a high nuclear and electromagneticradiation-shielding ability without using lead.

It is another object of the present invention to obtain a shieldmaterial having a high density without becoming bulky.

It is further another object of the present invention to provide ashield material comprising a composite material consisting of aradiation-shielding material and an organic material, which is capableof providing higher strength and enhanced non-breakability againsttearing and/or shock to facilitate easy-handling.

It is still further another object of the present invention to obtain alead-free shield material which is hardly broken or cracked duringbending or folding.

According to a first aspect of the present invention, there is provideda shield material comprising: a flexible formed element having, forexample, a plate-like shape, of a composite material consisting of anorganic material as a base material and a dispersed powder materialhaving a nuclear or electromagnetic radiation-shielding ability; and acloth-like sheet formed of a flame-resistant fiber overwrapping saidflexible formed element, whereby flame resistance and strength duringhandling is improved. In addition, the shield material of the presentinvention has excellent flexibility enough to facilitate shaping duringdeformation working. Thus, according to the present invention, theshield material makes it possible to closely cover a target even if ithas a complicated shape so as to shield against various nuclear orelectromagnetic radiations emitted from the target having a complicatedsurface profile.

According to another aspect of the present invention, a shield materialimproved of strength against bending or folding is obtained by attachinga reiforcing material onto a surface or inside the composite elementconsisting of particles having a nuclear or electromagneticradiation-shielding ability and polymeric organic compound particleshaving elasticity.

Each of the organic material serving as a base material and theradiation-shielding material to be dispersedly mixed with the organicmaterial may be appropriately selected in consideration with a requiredradiation-shielding ability and conditions employed, such asenvironmental temperature.

Particularly, as for shielding against nuclear radiation, a nuclearradiation-shielding ability is proportional to the density of a nuclearradiation-shielding material. For example, tungsten or molybdenum has ahigh density and a significantly high nuclear radiation-shieldingability, about 1.4 times greater than that of lead in equivalent volume.And, similarly, one or more of tungsten carbide, other tungsten alloy orcompound and other heavy-metal alloy or compound may be mixed with otherhigh-density powder, such as tungsten or molybdenum, are expected toobtain the same effect.

As for shielding against electromagnetic radiation, as the shieldingdispersion material to be mixed with an organic material, magneticpowder material, such as iron material, iron oxide, titanium oxide orbarium titanate, may be suitably used. Generally, either one of anelectromagnetic radiation-reflecting function of a surface of the shieldmaterial and an electromagnetic radiation-absorbing function of theradiation-shielding material is utilized to shield againstelectromagnetic radiation. Particularly, when the shield material isapplied to an electromagnetic radiation measurement device, it isdesirable to utilize the absorption-based shielding, because reflectedelectromagnetic radiation in the reflection-based shielding is likely toexert adverse affects on another device. Thus, a magnetic metalliccompound capable of absorbing electromagnetic radiation throughconversion to heat may be suitably used as the shield material.

An organic material used in the present invention is preferable to haveflexibility and conformability to the aforementioned metal and metaloxide. An elastomer resin, a vulcanized rubber or a soft plastic ispreferably used.

As the flame-resistant cloth-like sheet for wrapping over the flexibleelement formed of the composite material having the radiation-shieldingability, a fiber member excellent in tearing strength, flexibility andflame resistance, such as a cloth-like woven fabric formed of glassfiber, metal fiber, carbon fiber or ceramic fiber is used.

By wrapping the fiber member around the flexible element in ahermetically-sealing manner, oxygen supply to the organic materialconstituting the composite material is blocked and flame resistance isfurther enhanced. The cloth-like sheet formed of the fiber is preferableto be coated with a non-air-permeable coating material, such as vinylchloride coating material.

Various ways can be applicable as desired, for wrapping the formedshielding material with a flame-resistant cloth-like sheet, inaccordance with the present invention. For example, forming a bag from aflame-resistant cloth-like sheet and hermetically enclosing the formedelement of the composite material in the bag, preliminarily wrapping thecomposite material with the cloth-like sheet and forming together to thefinal shape, and inserting the formed composite into the aperture of atleast two cloth sheets peripherally bound and sealing together, may beadaptable. On sealing the cloth-like sheets, joining the outerperipheries of the cloth-like sheets by stitching using a high-strengthnylon, glass-fiber or metal-fiber string, or thermo-compression bondingusing a welder, or adhesive bonding or sticking using adhesive.

As the reinforcing member, a laminate film of polyethylene, nylon,polyester or metal, a wire mesh formed of nylon fiber or metal fiber; ora plate- or rod-shaped member having a surface formed with a protrusionare applicable. The use of such reinforcing member allows the shieldmaterial to obtain enhanced bending and or shear strength in lessvolume. Thus, even if the reinforcing member is added, the reduction indensity of the shielding element is limited to an extremely small value,and thereby there is almost no deterioration in shielding abilityagainst nuclear or electromagnetic radiation. The reinforcing member maybe applied by cutting to be a suitable shape with the shieldingmaterial.

As a method for preparing the shielding element and the reinforcingmaterial into a unit by integrating, any suitable method such as keepingthe reinforcing member in contact with the shielding element andapplying heat onto the contact region therebetween to partly fuse thecontact region, adhesively attaching the reinforcing member to theshielding element, or setting the reinforcing member in two or more ofthe shielding elements and applying heat and pressure to them.

The shielding element integrated with the reinforcing member can beapplied to the aforementioned wrapping with the cloth-like sheet toprovide enhanced resistance against breakage and cracks duringtransportation or storage in a folded manner.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view showing one example of a shield material of thepresent invention, wherein a reinforcement member is attached onto onesurface of a shielding element.

FIG. 2 is a side view showing another example of the shield material ofthe present invention, wherein a reinforcement member is attached insidea shielding element.

FIG. 3 is a perspective view showing yet another example of the shieldmaterial of the present invention, wherein a reinforcement member isattached in the vicinity of one surface of a shielding element.

FIG. 4(a) is a side view showing still another example of the shieldmaterial of the present invention in a normal state, wherein areinforcement member capable of being bent only within a given bendingangle is attached onto one surface of a shielding element.

FIG. 4(b) is a side view showing the shield material in FIG. 4(a), inthe state after being folded.

FIG. 5 is a side view showing yet still another example of the shieldmaterial of the present invention, wherein the reinforcement member inFIG. 4(a) is attached onto each of opposite surfaces of the shieldingelement.

BEST MODE FOR CARRYING OUT THE INVENTION Example 1

Table 1 shows various examples where a shield material of the presentinvention is applied to a nuclear radiation shield.

In Table 1, samples Nos. 1 to 8 are Inventive Examples, and samples Nos.9 to 13 are Comparative Examples. Table 1 also shows evaluation resultsof flexibility, shielding ability, flame resistance, environmentalimpact and handling performance of each sample, and a comprehensiveevaluation thereof.

As dispersed particles for providing a nuclear radiation-shieldingability, a tungsten powder, a molybdenum powder and a hafnium oxide eachhaving a particle size of about 0.5 to 100 μm were prepared. Further, asan organic material, an olefin elastomer, a vulcanized rubber, a styreneelastomer, an isoprene elastomer and a polyester elastomer wereprepared. Then, each of the organic materials was mixed with each of thedispersed particles at a ratio of about 40 volume %, and the mixture waskneaded to obtain a composite material. The obtained composite materialwas subjected to warm pressing at a temperature of 140 to 180° C. toform a plate-shaped member of 3 mm×300 mm×1000 mm. Then, as a cloth-likesheet, a glass cloth sheet coated with vinyl chloride, a glass clothsheet coated with silicon, a carbon fiber sheet coated with silicon, atungsten wire sheet coated with PTFE (polytetrafluoroethylene), a steelwire sheet coated with PTFE, and a silicon carbide powder-containingnylon sheet coated with silicon were prepared, as shown in Table 1. Eachof the cloth-like sheets was formed into a bag or pouch shape having apocket of 3 mm (thickness)×300 mm×1000 mm. The plate-shaped member wasinserted into the pocket of the pouch, and then an opening of the pouchwas sewn with a polyester thread to obtain a shield material. Instead ofusing this shield material as a nuclear radiation shield at a fixedlocation for a long period of time, a location requiring nuclearradiation shielding was variously changed, and the shield material wasformed into various shapes depending on the locations. Specifically, theshield material was used as a nuclear radiation shield during anoperation for inspecting various locations in a nuclear power generationfacility.

Each of the samples No. 1 to 8 or Inventive Examples were evaluated asadequate in all items of flexibility, shielding ability, flameresistance, environmental impact and handling performance, and exhibitedexcellent properties as a nuclear radiation shield.

The shield material containing the high-density tungsten powder inInventive Examples exhibited excellent nuclear radiation shieldingperformance, which was superior to an X-ray shielding ability of thelead-containing samples Nos. 9 and 10 in equivalent thickness.

The sample No. 11 prepared by filling a vinyl-chloride (hereinafterreferred to as “VC” for brevity)-coated glass cloth sheet with an ironpowder could not be practically used due to uneven distribution of thepowder within the sheet and unevenness in shielding ability over thesheet.

The sample No. 12 having a plate-shaped member formed of atungsten-elastomer resin composite material and no cloth-like sheet washardly handled and easily broken due to poor bending and tearingstrengths.

The sample No. 13 having a cloth-like sheet made of polyethylene easilycaught fire even by short-time contact with flame. TABLE 1 SampleMaterial of plate-shaped Material of cloth- Shielding FlameEnvironmental Handling Comprehensive No. member like sheet FlexibilityAbility Resistance Impact Performance Evaluation 1 tungstenpowder-olefin VC-coated glass ∘ ∘ ∘ ∘ ∘ ∘ elastomer cloth sheet 2tungsten powder-vulcanized VC-coated glass ∘ ∘ ∘ ∘ ∘ ∘ rubber clothsheet 3 molybdenum powder-olefin VC-coated glass ∘ ∘ ∘ ∘ ∘ ∘ elastomercloth sheet 4 tantalum powder-vulcanized silicon-coated ∘ ∘ ∘ ∘ ∘ ∘rubber glass cloth sheet 5 hafnium oxide powder- silicon-coated ∘ ∘ ∘ ∘∘ ∘ vulcanized rubber carbon fiber sheet 6 tungsten powder-styrenePTFE-coated tung- ∘ ∘ ∘ ∘ ∘ ∘ elastomer sten wire sheet 7 tungstenpowder-isoprene PTFE-coated steel ∘ ∘ ∘ ∘ ∘ ∘ elastomer wire sheet 8tungsten powder-polyester silicon-coated ∘ ∘ ∘ ∘ ∘ ∘ elastomer siliconcarbide-containing nylon sheet 9 lead NON x ∘ ∘ x ∘ x 10 lead wool VCglass ∘ x ∘ x ∘ x cloth sheet 11 tungsten powder VC glass ∘ x ∘ ∘ ∘ xcloth sheet 12 tungsten powder-olefin NON ∘ ∘ x ∘ x x elastomer 13tungsten powder-olefin polyethylene ∘ ∘ x ∘ ∘ x elastomer film

Example 2

Table 2 shows various examples where a shield material of the presentinvention is applied to an electromagnetic radiation shield.

In Table 2, examples Nos. 21 to 23 are Inventive Examples. As anelectromagnetic radiation-shielding dispersed material, an iron oxidepowder and an iron powder were selected. Further, as an organicmaterial, a vulcanized rubber and an olefin elastomer were selected.Then, each of the organic materials was mixed with each of the dispersedmaterials at a ratio about 40 volume % to form a composite material, andthe composite material was treated in the same manner as that in Example1 to prepare a plate-shaped member of 1 mm×1000 mm×1000 mm.

As a cloth-like sheet, a VC-coated glass cloth sheet was selected, andtwo of the glass cloth sheets are prepared. Then, the plate-shaped sheetmade of the composite material was sandwiched between the glass clothsheets, and the outer periphery of the glass cloth sheets was integrallyjoined to the plate-shaped sheet sandwiched therebetween, throughthermo-compression bonding using a welder to obtain a shield material.

A plurality of the shield materials were prepared, and used as anelectromagnetic radiation shield in such a manner as to be adhesivelyattached onto an outer wall of a simple electromagnetic radiation shieldroom.

The shield material is required to have flexibility enough to closelycover the outer wall of the electromagnetic radiation shield room,because the outer wall is formed with a number of protrusions. Theshield material is also required to have a high strength against tearingor the like without eliminating the need for paying particular attentionto its handling when the location of a target facility is changed, orthe shield material is used in another target facility. If the shieldmaterial has a low shielding ability per volume, it has to be formed asa thick shield. This is disadvantage in carrying, installation in afacility, or storage thereof. Thus, it is desirable that the shieldmaterial has a high shielding ability per volume. In terms of theseneeds, the samples Nos. 21 to 23 or Inventive Examples were a suitableelectromagnetic radiation shield material. In addition, these samplesalso had excellent non-breakability and flame resistance, as well asadequate flexibility.

In Table 2, samples Nos. 24 to 27 are Comparative Examples. As comparedto these Comparative Examples, the samples Nos. 21 to 23 or InventiveExamples were superior as an electromagnetic radiation shield in allitems of flexibility, shielding ability, flame resistance, environmentalimpact and handling performance.

The sample No. 24 prepared by filling a VC-coated glass cloth sheet withan iron powder could not be practically used due to uneven distributionof the powder within the sheet and unevenness in shielding ability overthe sheet. The sample No. 25 having a plate-shaped member formed of aniron oxide-elastomer resin composite material and no cloth-like sheetwas hardly handled and easily broken. The sample No. 26 having acloth-like sheet made of polyethylene easily caught fire even byshort-time contact with flame. Further, the sample No. 27 having aplate-shaped member formed of an iron plate had poor conformability tosurface profiles of facilities, and could be used only in limitedfacilities having a specific surface profile. TABLE 2 Sample ShieldingFlame Handling Comprehensive No. Material of plate-shaped memberMaterial of cloth-like sheet Flexibility Ability Resistance PerformanceEvaluation 21 iron oxide powder-vulcanized rubber VC-coated glass clothsheet ∘ ∘ ∘ ∘ ∘ 22 iron oxide powder-olefin elastomer VC-coated glasscloth sheet ∘ ∘ ∘ ∘ ∘ 23 iron powder-olefin elastomer silicon-coatedglass cloth sheet ∘ ∘ ∘ ∘ ∘ 24 iron oxide powder VC-coated glass clothsheet ∘ x ∘ ∘ x 25 iron powder-olefin elastomer NON ∘ ∘ x x x 26 ironoxide powder-vulcanized rubber polyethylene ∘ ∘ x ∘ x 27 iron plate NONx ∘ ∘ x x

Example 3

FIGS. 1 to 5 show various examples of a shield material with areinforcing member of the present invention.

When a shielding element 1 comprises a mixture of particles having aradiation shielding ability and a flexible polymer compound, itadditionally includes a reinforcing member 2 integrally attachedthereto. The reinforcing member 2 may be attached to the shieldingelement 1 in the following manners. As shown in FIG. 1, when thereinforcement member 2 has a film shape or a mesh shape, it may beattached onto one surface of the shielding element 1. Alternatively, asshown in FIG. 2, the reinforcement member 2 may be embedded in theinside of the shielding element 1.

Further, as shown in FIG. 3, when a reinforcement member 20 has aplurality of protrusions 21 formed on one surface thereof, it may bearranged to allow the protrusions 21 to face downward, and thenintegrally embedded in the vicinity of one surface of the shieldingelement 1.

Further, in the reinforcement member 20 having the protrusions 21, theprotrusions 21 can control a curvature of the shielding element 1 insuch as manner as to prevent the shielding element 1 from being bentbeyond a given bending angle in a specific direction, as shown in FIG.4(b). For example, when the shielding element is formed as a mat-shapedelongated member, this reinforcement member 20 may be attached on thecentral region of one surface of the elongated member along thelongitudinal direction thereof. Thus, even if the elongated member isfolded for transfer or storage, a curvature of the folded portion can bemaintained at a given value or more to prevent the occurrence ofbreakage or cracks therein.

In Example 3, a tungsten powder having a high nuclear radiationshielding ability was used as a metal for a shielding element, and anolefin elastomer (thermoplastic elastomer) powder was used as an organicmaterial for the shielding element. These were mixed, heated and pressedto obtain a plate-shaped composite material consisting of 60 volume % oftungsten powder and 40 volume % of olefin elastomer. Further, a cohesivelaminate sheet primarily containing a resin component was selected asthe reinforcing member, and cut off in conformity to a shape of theplate-shaped composite material to prepare two laminate sheets. Then,the two laminate sheets were adhesively attached, respectively, ontoopposite surfaces of the plate-shaped composite material, and integratedwith the plate-shaped composite material, to obtain a plate-shapedflexible shield material.

The obtained shield material was used as a curtain of an X-rayfluoroscope for security screening, which has been conventionally madeof a lead-containing shield material.

This shield curtain had excellent nuclear radiation-shieldingperformance based on the high-density tungsten powder contained therein,and exhibited an X-ray shielding ability superior to that of alead-containing shield in equivalent thickness. The shield curtain alsohad excellent flexibility, and could be deformed in a bending manner.Further, even if a baggage was a food item, the shield curtaincontaining no harmful material, such as lead, could be used without aproblem about lead pollution of foods. Furthermore, the shield curtainhad a higher tearing strength than that of the conventional shield tofacilitate attachment, and could obtain a durable term equal to orlonger than that of the conventional curtain made of the lead-containingshield material.

Example 4

As a shielding element, the same plate-shaped composite material as thatin Example 3 was selected. Further, as a reinforcing member 20, a resinplate having a plurality of protrusions 21 as shown in FIG. 4 wasselected, and cut off in conformity to a size of the plate-shapedcomposite material to prepare two reinforcing members. Then, thereinforcing members are attached onto the composite material with anadhesive to obtain a shield material 1 having opposite surfaces eachformed with a plurality of convex and concave portions defining groovestherebetween, as shown in FIG. 5. The obtained shield material was usedas a nuclear radiation shield during an operation for inspecting variouslocations in a nuclear power generation facility. Instead of using thisshield material as a nuclear radiation shield at a fixed location for along period of time, the nuclear radiation shield was used at variouslocations to be changed according to the inspection operation.

This shield had flexibility sufficient to be deformed in conformity tovarious shapes. In addition, when the shield was folded duringtransport, the reinforcing member allowed the folded portion to reliablyhave a given curvature or more without cracks in the composite material.Further, the shield had a nuclear-radiation shielding performance whichis two times greater than that of a lead wool mat in equivalentthickness.

As a comparative example, the same shielding element without thereinforcing members was used during the inspection operation in thenuclear power generation facility. This shield could not stand long usedue to cracks occurring in the composite material during transport.

Example 5

A ferrite powder having a high electromagnetic radiation-absorbingcapacity was selected as a metal for a shielding element, and avulcanized rubber powder was used as an organic material for theshielding element. Then, a plate-shaped shielding element consisting of60 volume % of ferrite and 40 volume % of vulcanized rubber was obtainedin the same manner as that in Example 1. This shielding element wasformed into a plate shape of 500 mm square by 1 mm thickness. Two of theshielding elements were prepared, and a lattice-shaped copper net havinga diameter of 0.05 mm and a pitch of 1 mm was sandwiched between theshielding elements. These three components are heated and pressed fromboth opposite surfaces, and integrated together to obtain a shieldmaterial. The copper net was embedded in the central region of theintegrated shielding elements, and firmly joined thereto.

The obtained electromagnetic radiation shield was closely attached ontoa wall and ceiling of a simple electromagnetic radiation measurementroom. As a result, a noiseless measurement could be performed with ahigh degree of accuracy, without any external electromagnetic wave witha frequency of 2 MHz or more. The electromagnetic radiation shield hadno breakage and crack even though it was bent during attachment and usedin this state, and had flexibility conformable to a shape of themeasurement room.

INDUSTRIAL APPLICABILITY

The shield material of the present invention can be convenientlyattached onto any portion or member requiring shielding againstelectromagnetic radiation or nuclear radiation from nuclear facilities.

In addition, the shield material of the present invention having novenomousness can be used for various purposes, such as a detectiondevice for a metal remaining in foods, and a curtain of an X-ray baggagescreening apparatus in airports.

1. A shield material comprising: a flexible element formed of acomposite material consisting of an organic material and a dispersedmaterial having a nuclear or electromagnetic radiation-shieldingability; and a cloth-like sheet formed of a flame-resistant fiber,wherein said flexible element is wrapped with said cloth-like sheet. 2.The shield material as defined in claim 1, wherein said dispersedmaterial is a heavy-metal powder, and said shied material is used for anuclear radiation shield.
 3. The shield material as defined in claim 1,wherein said dispersed material is one selected from the groupconsisting of a metallic iron, an iron oxide and a dielectric materialbeing capable of absorbing electromagnetic radiation, and said shiedmaterial is used for an electromagnetic radiation shield.
 4. The shieldmaterial as defined in claim 1, wherein said flame-resistant fiber iseither one selected from the group consisting of glass fiber, metalfiber, carbon fiber and ceramic fiber.
 5. The shield material as definedin claim 1, wherein said cloth-like sheet is coated with a non-airpermeable coating material.
 6. A shielding material attached with areinforcing member having reinforcing ability against bending, onto ashielding element consisting of an elastic polymeric organic compounddispersed with a dispersed material having a nuclear or electromagneticradiation-shielding ability.
 7. The shield material as defined in claim6, wherein said dispersed material consists of a heavy metal or amagnetic material and said elastic polymeric organic compound consistsof an elastomer resin or a vulcanized rubber.
 8. The shield material asdefined in claim 6, wherein said reinforcing member is at least oneselected from the group consisting of a film made of polyethylene, nylonor metal, a wire mesh formed of nylon fiber or metal fiber, and a plate-or rod-shaped member having a surface formed with a protrusion.
 9. Theshield material as defined in claim 6, wherein said reinforcing memberis attached onto or in the vicinity of a surface, or inside saidshielding element.
 10. The shield material as defined in claim 6,wherein said reinforcing member is attached to said shielding element insuch a manner as to be compression-bonded thereto.
 11. The shieldmaterial as defined in claim 6, wherein said reinforcing member isattached to said shielding element in such a manner as to becompression-bonded between two divided pieces of said shielding element.12. The shield material as defined in claim 6, which further includes acloth-like sheet which is wrapped around the integral structure of saidshielding element and said reinforcing member attached thereto, saidcloth-like sheet being interweaved with a high-strength fiber which iseither one selected from the group consisting of glass fiber, metalfiber and nylon fiber.